This routine is a patch which breaks the copy protection
of Accolade's Mean 18 golf game for the IBM PC.
Written by Kent Briggs 8/21/88
** Do not modify your original disk **
Copy all your files to another disk or to a subdirectory
on your hard disk and put the original disk away in a safe place.
Mean 18 does not indicate a version number but the file size
for GOLF.EXE should be 89375 bytes. The copy protection scheme
looks for a bad sector on drive A. We will patch 4 calls to this
routine with NOP's (no operation) and patch 1 JUMP to an early exit
with a NOP.
Put DEBUG.COM (from your DOS disk) in the same directory or make sure
it is in the DOS path. Type the following commands:
Command Comments
======= ========
ren golf.exe golf.xxx Rename program for debug
debug golf.xxx Load debug
rcs Check contents of cs register
(retype the 4 digits shown, but The code that we want to change
add 1 to the left digit first) is beyond the current 64K segment
e cs:4fe3 90 90 90 NOP the first call
e cs:4fec 90 90 90 NOP the second call
e cs:500a 90 90 90 NOP the third call
e cs:5019 90 90 90 NOP the fourth call
e cs:5058 90 90 NOP the early exit jump
rcs Check cs register again
(retype the 4 digits shown, but Restore the cs register to its
subtract 1 from the left digit first) original state
w Write file back to the disk
q Quit debug
ren golf.xxx golf.exe Restore file name
======= ========
Now run GOLF and confirm that the patch works.
The Course Architect program (ARCH.EXE) is also copy protected with an
identical scheme. The size of ARCH.EXE should be 49631 bytes. No
segment registers have to be altered since all the code will fit into
1 segment.
Command Comments
======= ========
ren arch.exe arch.xxx Rename program for debug
debug arch.xxx Load debug
e bd9a 90 90 90 NOP the first call
e bda3 90 90 90 NOP the second call
e bdc1 90 90 90 NOP the third call
e bdd0 90 90 90 NOP the fourth call
e be0f 90 90 NOP the early exit jump
w Write file back to the disk
q Quit debug
ren arch.xxx arch.exe Restore file name
======= ========
Now run ARCH and confirm that the patch works.